1. Technical Field
The invention relates to motor vehicle controls and more particularly to controls relating to specialized or auxiliary equipment for special purpose vehicles, such as passenger embarkation/disembarkation warning systems for school busses.
2. Description of the Problem
Driver controls for motor vehicles are better positioned if consideration is given to the tasks and distractions likely to be confronting the driver while using the controls. A consequence of such considerations is that motor vehicle designers now commonly locate speed control switches on the vehicle's steering wheel. A driver is likely to be maneuvering the vehicle when activating and deactivating the speed control system or when adjusting the settings of the speed control system. It is undesirable that the driver be distracted from driving by removing his hands from the steering wheel while doing so.
Depending upon the intended use of a vehicle, different criteria might govern the placement of controls. Of particular interest to the present invention are how the activities of a bus driver, particularly a school bus driver, might influence the choice of control location. Analysis of school bus drivers' activities behind the wheel has indicated that, as might be expected, that the activation of door controls, warning lights and stop arms demands the most hand movements.
The control electronics for contemporary motor vehicles make increasing use of programmable, digital electronics to receive driver inputs from control switches and to route control signals to devices. The switches on the vehicle steering wheel are no longer typically hard wired to the devices they control, but rather the outputs from the switches are interpreted by a digital computer and the appropriate control signals generated and routed to a controller for the intended device. This eases decisions regarding the location of switches since wires do not have to be routed from switch to controlled device. It also means that the functions of particular switches are not necessarily fixed. The Society of Automotive Engineers (SAE) has published standards relating to motor vehicle digital control networks and communications, including the J1708 and J1939 standards.